1. Field of the Invention
The present invention relates to a data superimposing device in a camera that superimposes an image representing information such as the shooting date and time on a film.
2. Description of the Related Art
There are conventional data superimposing devices of this kind in which a plurality of light emitting elements arranged vertically are selectively caused to emit light in synchronism with the running of the film, and a data image representing photographic data including the shooting date and time is superimposed over the picture on the film by causing the luminous flux from these light emitting elements to form the data image on the film through an optical system.
In the conventional data superimposing device, a circuit board on which the light emitting elements are mounted is arranged in the vicinity of the aperture, and it is required to secure a space for arranging this circuit board in the vicinity of the aperture, entailing a problem that the dimensions, especially the lateral dimension, of the camera are inevitably enlarged.
In order to solve this problem, Japanese Patent Application Publication No. 7-295061 discloses that a data superimposing light path is formed between the film take-up spool chamber and the photographic light path of the camera, one end of the data superimposing light path is disposed to face the film, and the other end is arranged at the circuit board on which light emitting elements are mounted. In this data superimposing device, with a view to further space saving within the camera, the data superimposing light path is bent along the curved wall surface of the take-up spool chamber by refracting the luminous flux from the light emitting elements a plurality of times by using a mirror and a prism. However, the use of the mirror and the prism involves a disadvantage of increasing the number of components and complicating the structure.
Japanese Patent Application Publication No. 2000-352756 discloses that a data superimposing light path is formed between the take-up spool chamber and the photographic light path of the camera, and space saving within the camera is attempted by installing at an inclination to the film surface an image-forming lens for causing a luminous flux from light emitting elements to form a data image on the film surface. However, this technique entails a disadvantage of manufacturing difficulty because the image-forming lens should be held at an inclination.
Furthermore, the formation of a data superimposing light path in the limited space between the take-up spool chamber and the photographic light path as according to Japanese Patent Application Publication Nos. 7-295061 and 2000-352756 has another disadvantage that a flare may arise and blur the superimposed data image.
An object of the present invention, attempted in view of these circumstances, is to provide a data superimposing device for cameras which is compactly structured and allows clear superimposition of data.
In order to attain the above-described object, the present invention is directed to a data superimposing device in a camera for superimposing an image representing data on a film, comprising: a light emitting unit which has a plurality of light emitting points emitting a luminous flux in synchronism with a running of the film to superimpose the image on the film, the light emitting unit being arranged in a space formed between an outer wall surface of a photographic light path shielding cylinder and an arc-shaped outer wall surface of one of a film cartridge chamber and a film take-up spool chamber; an image-forming lens which is arranged in the space and causes the luminous flux to form the image on the film; and an aperture member which has an aperture through which the luminous flux travels to reach the film, the aperture being arranged at a narrowest position of the space.
According to the present invention, by providing the aperture in the narrowest position of the space formed between the outer wall surface of the photographic light path shielding cylinder and the arc-shaped outer wall surface of the cartridge chamber or the take-up spool chamber, the space, though limited in size, is expanded before and behind the aperture to make possible effective flare suppression and clear superimposition of the data on the film.
Preferably, the image-forming lens is arranged immediately behind the aperture. According to the present invention, by providing the image-forming lens, like the aperture, in the narrowest position of the space, the image-forming lens can be easily fitted without having to incline it.
The image-forming lens may be installed by being pressed in through a fitting hole bored in an inner wall of the one of the film cartridge chamber and the film take-up spool chamber from a side of the one of the film cartridge chamber and the film take-up spool chamber. According to the present invention, installation of the image-forming lens by pressing it in through the fitting hole bored in the wall surface of the cartridge chamber or the take-up spool chamber from the side of the cartridge chamber or the take-up spool chamber makes it possible to hold the image-forming lens accurately even if the wall of the cartridge chamber or the take-up spool chamber is thin.